This invention relates to an apparatus for peeling a record paper having a toner image transferred thereto off a charge retentive member in an electrophotographic copying machine.
In many electrophotographic copying machines an electrostatic charge image formed on a charge retentive drum is developed with a dry toner developing agent to form a toner image and then the toner image is transferred onto a record paper by means of a transferring member. In such a copying machine a transfer roller is usually provided for pressing the record paper against the charge retentive drum and the record paper is liable to be stuck onto the charge retentive drum. Therefore there is provided an apparatus for peeling the record paper having the toner image transferred thereon off the charge retentive drum.
In U.S. patent application Ser. No. 30,629 filed on Apr. 19, 1979, and assigned to the same assignee as the present invention, now abandoned a paper peeling apparatus for use in an electrophotographic copying machine, said peeling apparatus comprising a pair of pawls each for peeling a respective side edge of the record paper off the charge retentive member, first and second guide plates arranged substantially in parallel with each other for defining a passage for the record paper, a duct for supplying an air stream into a space between the record paper and charge retentive member, and a plurality of openings formed in the first guide plate for passing an air stream into said passage so as to press the record paper against the second guide plate.
In a preferred embodiment said air stream is produced by a fan which generates a suction air stream for collecting residual toner particles removed from the charge retentive member by a rotating cleaning brush.
In such a peeling apparatus there can be obtained advantage that the record paper can be effectively peeled off the charge retentive member although a construction is simple and the number of necessary parts is small. After conducting various tests for this peeling apparatus the inventor has found that the pawls can initiate the peeling operation and the side edges of record paper are at first separated from the charge retentive drum, but at this time a central portion of record paper is still made in contact with the drum. Therefore the front edge of record paper is curved toward the drum. When the paper is curved, its regidity becomes large and thus it is rather difficult to change the feeding direction of the record paper along the transfer roller. Therefore the front edge of record paper sometimes strikes against a front edge of first guide plate and might be jammed. Further the record paper has the toner image which has not yet been fixed on that surface which is brought into contact with the inner surface of first guide plate. Thus the toner image on the record paper might be damaged or deteriorated.